Cell stack device, module, and module housing device

ABSTRACT

A cell stack in which a plurality of cells may have a cylindrical shape and may include gas flow passages may be arranged uprightly and may be electrically connected may include: a manifold configured to fix lower ends of the plurality of cells and supply gas to the gas flow passages of the plurality of cells, and a gas supply pipe configured to supply the gas to the manifold. The gas supply pipe may include one end connected to a gas supply portion and another end inserted into a first through hole provided in the manifold, and may be joined to the manifold via a first joining portion. The gas supply pipe may include a first protruding portion protruding toward an inner side of the gas supply pipe and located at a position corresponding to the first joining portion in any cross-section along an insertion direction of the gas supply pipe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage entry according to 35 U.S.C. 371 ofPCT Application No. PCT/JP2018/011783 filed on Mar. 23, 2018, whichclaims priority to Japanese Application No. 2017-086310 filed on Apr.25, 2017, which are entirely incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a cell stack device, a module, and amodule housing device.

BACKGROUND

In recent years, as a next-generation energy source, for example, JP5766132 B (hereinafter, referred to as PTL 1) discusses a cell stackdevice in which a plurality of fuel cells are arranged in a manifold.The fuel cells are cells that may be capable of obtaining electricalpower by using fuel gas (hydrogen-containing gas) and oxygen-containinggas (air).

Further, for example, JP 5873949 B (hereinafter, referred to as PTL 2)discusses a device in which a manifold may include an introduction pipeconfigured to introduce gas to an internal space of the manifold, oneend portion of the introduction pipe may be inserted into a through holeprovided in the manifold, and the introduction pipe and the manifold maybe joined via a joining portion.

SUMMARY

A cell stack device according to a non-limiting embodiment of thepresent disclosure may include a cell stack in which a plurality ofcells may have a cylindrical shape and may include gas flow passages maybe arranged uprightly and may be electrically connected may include amanifold configured to fix lower ends of the plurality of cells andsupply gas to the gas flow passages of the plurality of cells, and a gassupply pipe configured to supply the gas to the manifold. The gas supplypipe may include one end connected to a gas supply portion and anotherend inserted into a first through hole provided in the manifold, and maybe joined to the manifold via a first joining portion. The gas supplypipe may include a first protruding portion protruding toward an innerside of the gas supply pipe and located at a position corresponding tothe first joining portion in any cross-section along an insertiondirection of the gas supply pipe.

A module according to a non-limiting embodiment of the presentdisclosure may include the cell stack device housed in a housingcontainer.

A module housing device according to a non-limiting embodiment of thepresent disclosure may include the module and an auxiliary deviceconfigured to operate the module. The module and the auxiliary devicemay be housed in an external casing.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view and a partial cross-sectional view illustrating anon-limiting example of a cell stack device according to a non-limitingembodiment.

FIG. 2A is an enlarged vertical cross-sectional view illustrating anon-limiting example of section A in FIG. 1, and FIG. 2B is a horizontalcross-sectional view taken along line X-X in FIG. 2A.

FIG. 3A is a horizontal cross-sectional view illustrating anothernon-limiting example of FIG. 2B.

FIG. 3B is a horizontal cross-sectional view illustrating anothernon-limiting example of FIG. 2B.

FIG. 3C is a horizontal cross-sectional view illustrating anothernon-limiting example of FIG. 2B.

FIG. 4 is an enlarged vertical cross-sectional view illustrating anothernon-limiting example of section A of FIG. 1.

FIG. 5 is an enlarged vertical cross-sectional view illustrating anothernon-limiting example of section A of FIG. 1.

FIG. 6A is an external perspective view illustrating anothernon-limiting example of a cell stack device according to a non-limitingembodiment.

FIG. 6B is a plan view of the manifold illustrated in FIG. 6A.

FIG. 7 is a cross-sectional view taken along line Y-Y in FIG. 6B withsome portions being illustrated in a side view.

FIG. 8A is an enlarged vertical cross-sectional view illustrating anon-limiting example of section B in FIG. 7, and FIG. 8B is a horizontalcross-sectional view taken along line Z-Z in FIG. 8A.

FIG. 9A is a horizontal cross-sectional view illustrating anothernon-limiting example of FIG. 8B.

FIG. 9B is a horizontal cross-sectional view illustrating anothernon-limiting example of FIG. 8B.

FIG. 9C is a horizontal cross-sectional view illustrating anothernon-limiting example of FIG. 8B.

FIG. 10 is an enlarged vertical cross-sectional view illustratinganother non-limiting example of section B of FIG. 7.

FIG. 11 is an enlarged vertical cross-sectional view illustratinganother non-limiting example of section B of FIG. 7.

FIG. 12 is an external perspective view illustrating a non-limitingexample of a module according to a non-limiting embodiment.

FIG. 13 is a perspective view illustrating a non-limiting example of amodule housing device according to a non-limiting embodiment with aportion of the module housing device not being illustrated.

DETAILED DESCRIPTION

With reference to FIGS. 1 to 13, description will be made of anon-limiting example of a cell stack device, a module, and a modulehousing device according to various non-limiting aspects of the presentdisclosure.

FIG. 1 is a side view illustrating a non-limiting example of the cellstack device according to a non-limiting embodiment and a portion of thecell stack device is illustrated in a partial cross-sectional view forease of understanding. Further, FIG. 2A is an enlarged verticalcross-sectional view illustrating a non-limiting example of section A inFIG. 1, and FIG. 2B is a horizontal cross-sectional view taken alongline X-X in FIG. 2A. Note that in the subsequent figures, the samemembers will be denoted by the same reference signs.

In a cell stack device 1 illustrated in FIG. 1, cells 3 are arrangeduprightly in a row, and each include a gas flow passage (notillustrated) through which gas flows from one end to another end insidethe cell. The cells 3 adjacent to each other are electrically connectedin series via a conductive member (not illustrated). Moreover, the cellstack device 1 illustrated in FIG. 1 includes one cell stack 5 in whichlower ends of the cells 3 are fixed to a manifold 4 with an insulatingadhesive (not illustrated) such as a glass sealing material.

Further, a reformer 6 serving as a gas supply portion configured togenerate gas to be supplied to the cells 3 is disposed above the cellstack 5. Note that in the following description, the gas supply portionwill be described as the reformer 6 unless otherwise noted.

Further, an end conductive member 11 is disposed at an end portion ofthe cell stack 5. The end conductive member 11 includes a conductiveportion 12 and is configured to collect electricity generated by powergeneration in the cell stack 5 (cells 3) and draw the electricity to theoutside.

Note that the cell stack device 1 can also include the reformer 6.

Further, a hollow flat plate-shaped cell including a plurality of gasflow passages in which gas flows in a lengthwise direction is given as anon-limiting example of the cell 3 in FIG. 1. The cell 3 is a solidoxide cell formed by sequentially stacking an inner electrode layer, asolid electrolyte layer, and an outer electrode layer on a surface of asupport body including the gas flow passages. Note that in the followingdescription, the inner electrode layer will be described as a fuelelectrode layer, and the outer electrode layer will be described as anoxygen electrode layer unless otherwise noted.

Here, in the cell 3, a portion in which the fuel electrode layer and theoxygen electrode layer face each other, via the solid electrolyte layer,functions as a power generating element. That is, oxygen-containing gassuch as air flows outside the oxygen electrode layer, and fuel gas(hydrogen-containing gas) flows in the gas flow passages inside thesupport body. The oxygen-containing gas and the fuel gas are heated to apredetermined actuation temperature to generate power. Then, electricalcurrent generated by such power generation is collected via the endconductive member 11 described above.

Further, the reformer 6 illustrated in FIG. 1 reforms raw fuel such asnatural gas and kerosene supplied via a raw fuel supply pipe 10, andgenerates gas. Note that the reformer 6 can adopt a structure capable ofperforming steam reforming that is very efficient reforming reaction,and includes a vaporizing portion 7 configured to vaporize water and areforming portion 8 in which a reforming catalyst (not illustrated) thatreforms raw fuel into gas is disposed. Then, the gas generated in thereformer 6 is supplied to the manifold 4 via a gas supply pipe 9, and issupplied from the manifold 4 to the gas flow passages provided insidethe cells 3.

Note that in FIG. 1, the gas supply pipe 9 and the manifold 4 areillustrated in a cross-sectional view, and the rest is illustrated in aside view.

Further, in a non-limiting embodiment, the gas supply pipe 9 includesone end connected to the reformer 6, and another end inserted into afirst through hole 14 provided in the manifold 4, and is joined to themanifold 4 via a first joining portion 17.

Meanwhile, in the cell stack device 1, in a case where the gas supplypipe 9 is deformed or moves due to heat generated at the time of powergeneration of the fuel cells, there may be a risk that cracking orchipping due to fatigue breakage or the like may be generated in thefirst joining portion 17 between the gas supply pipe 9 and the manifold4, depending on the shape of the gas supply pipe 9. Thus, there has beenroom for improvement in firmly joining the gas supply pipe 9 and themanifold 4.

In view of this, in a non-limiting embodiment, as illustrated in FIG.2A, the gas supply pipe 9 includes a first protruding portion 19protruding toward an inner side of the gas supply pipe 9 and located ata position corresponding to the first joining portion 17. Accordingly,even when the gas supply pipe 9 is deformed or moves, due to the firstprotruding portion 19, a thickness t1 of the gas supply pipe 9 at thefirst protruding portion 19 is increased at the position correspondingto the first joining portion 17, and thus cross-sectional area of thegas supply pipe 9 increases, and generation of cracking or chipping dueto fatigue breakage or the like in the first joining portion 17 joinedto the gas supply pipe 9 can be suppressed. Accordingly, the gas supplypipe 9 and the manifold 4 can be joined firmly, and as a result, joiningreliability between the gas supply pipe 9 and the manifold 4 can beimproved.

Here, as illustrated in FIG. 2A and FIG. 2B, the thickness t1 of the gassupply pipe 9 at the first protruding portion 19 is a thickness obtainedby adding a maximum thickness t12 of the first protruding portion 19 toa thickness t11 of the gas supply pipe 9 itself.

As illustrated in FIG. 2B, the first protruding portion 19 can beprovided along an entire circumference of an inner surface of the gassupply pipe 9 from a viewpoint of increasing the cross-sectional area ofthe gas supply pipe 9. Accordingly, generation of cracking or chippingdue to fatigue breakage or the like in the first joining portion 17joined to the gas supply pipe 9 can be suppressed.

Each of FIG. 3A, FIG. 3B, and FIG. 3C is a horizontal cross-sectionalview illustrating another non-limiting example of FIG. 2B.

Each of FIG. 3A and FIG. 3B illustrates a non-limiting example in whicha thickness of the gas supply pipe 9 at the first protruding portion 19is uneven along an entire circumference.

As in FIG. 3A, a thin portion and a thick portion may beline-symmetrical. Further, as in FIG. 3B, the thin portion and the thickportion may be eccentric. As described above, even when the thickness ofthe gas supply pipe 9 at the first protruding portion 19 is uneven alongthe entire circumference, the gas supply pipe 9 remains thick withoutchange, and generation of cracking or chipping due to the portion can besuppressed.

On the other hand, the first protruding portion 19 is not necessarilyrequired to be provided along the entire circumference. As in FIG. 3C,the first protruding portion 19 may be provided partially. Even in thecase where the first protruding portion 19 is provided partially asdescribed above, generation of cracking or chipping due to the portionat which the gas supply pipe 9 is thick can be suppressed.

The thickness of the gas supply pipe 9 can be, for example, from 0.5 mmto 1.0 mm, and the thickness of the first protruding portion 19 can be,for example, from 0.1 mm to 0.5 mm.

Each of FIG. 4 and FIG. 5 is an enlarged vertical cross-sectional viewillustrating another non-limiting example of section A of FIG. 1.

In a non-limiting example illustrated in FIG. 4, a first bent portion 4c extending toward the reformer 6 side along the gas supply pipe 9 isprovided in an outer periphery of the first through hole 14 in themanifold 4, and an upper end portion of the first bent portion 4 c andthe gas supply pipe 9 are joined via the first joining portion 17. Themanifold 4 includes the first bent portion 4 c, and thus the manifold 4and the gas supply pipe 9 are joined easily. Further, the gas supplypipe 9 is inserted into the first through hole 14 easily. Note that aheight H1 of the first bent portion 4 c can be, for example, from 2 mmto 5 mm.

In the non-limiting example illustrated in FIG. 5, a thickness t3 of theupper end portion of the first bent portion 4 c is larger than athickness t4 of a center portion the first bent portion 4 c and smallerthan a thickness t5 of a lower end portion of the first bent portion 4c. In other words, the first bent portion 4 c has such a shape that thecenter portion is recessed with respect to the upper end portion and thelower end portion expands. Accordingly, cross-sectional area of theupper end portion of the first bent portion 4 c increases, and hence theupper end portion of the first bent portion 4 c and the gas supply pipe9 are firmly joined via the first joining portion 17. Moreover, thecenter portion is recessed with respect to the upper end portion of thefirst bent portion 4 c, and thus the thickness t4 of the center portionis the smallest among the thickness t3, the thickness t4, and thethickness t5. This center portion having a small thickness can relievestress generated when the gas supply pipe 9 is deformed or moves.Accordingly, the gas supply pipe 9 and the manifold 4 can be joinedfirmly. Furthermore, the lower end portion of the first bent portion 4 cexpands, and accordingly an angle formed between the first bent portion4 c and the manifold 4 is obtuse to obtain a gently-sloping shape.Hence, stress generated when the gas supply pipe 9 is deformed or movescan be relieved. As a result, generation of cracking or chipping betweenthe first bent portion 4 c and the manifold 4 can be suppressed.

At the first bent portion 4 c, the thickness t3 can be, for example, 0.6mm to 0.8 mm, the thickness t4 can be, for example, 0.5 mm to 0.6 mm,and the thickness t5 can be, for example, from 0.9 mm to 1.2 mm.

FIG. 6A is an external perspective view illustrating another example ofa cell stack device according to a non-limiting embodiment, and FIG. 6Bis a plan view of the manifold illustrated in FIG. 6A. Further, FIG. 7is a cross-sectional view taken along line Y-Y in FIG. 6B andillustrating a gas supply pipe 9, a manifold 4, and a flow control plate16, and the rest is illustrated in a side view.

The manifold 4 of a cell stack device 111 illustrated in FIG. 6A, FIG.6B, and FIG. 7 includes a main body portion 4 a including a spacecommunicated with gas flow passages, and a flange portion 4 b protrudingfrom the main body portion 4 a. Gas is supplied to cells 3 via the spacein the main body portion 4 a. Another end of the gas supply pipe 9 isinserted from a first surface n1 side into a first through hole 14provided penetrating the flange portion 4 b, and is joined to themanifold 4, and is further inserted from a second surface n2 side into asecond through hole 15 provided penetrating the main body portion 4 aand is joined with the manifold 4. Then, the manifold 4 includes theflow control plate 16 spaced apart from the other end of the gas supplypipe 9 and covering the other end. In other words, to improve a flowdistribution ratio, the flow control plate 16 is providedperpendicularly to a flow-out direction of gas flowing out through thesecond through hole 15. Further, the flow control plate 16 includes anopening portion. The opening portion may be provided such that the gasflows toward the cells 3 at an end portion of a cell stack 5 being awayfrom the flow control plate 16. Note that, the first surface n1 and thesecond surface n2 refer to, in the manifold 4, a surface on the side onwhich the cell stack 5 is joined and mounted, and a surface on theopposite side to the first surface, respectively.

FIG. 8A is an enlarged vertical cross-sectional view illustrating anon-limiting example of section B in FIG. 7, and FIG. 8B is a horizontalcross-sectional view taken along line Z-Z in FIG. 8A. In a non-limitingembodiment, the other end of the gas supply pipe 9 and the manifold 4are joined via a second joining portion 18. Here, in a non-limitingembodiment, as illustrated in FIG. 8A, the gas supply pipe 9 includes asecond protruding portion 20 protruding toward an inner side of the gassupply pipe 9 and located at a position corresponding to the secondjoining portion 18. Accordingly, even when the gas supply pipe 9 isdeformed or moves, due to the second protruding portion 20, a thicknesst2 of the gas supply pipe 9 at the second protruding portion 20 isincreased at the position corresponding to the second joining portion18, and thus cross-sectional area of the gas supply pipe 9 increases,and generation of cracking or chipping due to fatigue breakage or thelike in the second joining portion 18 joined to the gas supply pipe 9can be suppressed. Accordingly, the gas supply pipe 9 and the manifold 4can be joined firmly, and as a result, joining reliability between thegas supply pipe 9 and the manifold 4 can be improved.

Here, as illustrated in FIG. 8A and FIG. 8B, the thickness t2 of the gassupply pipe 9 at the second protruding portion 20 is a thicknessobtained by adding a maximum thickness t22 of the second protrudingportion 20 to a thickness t21 of the gas supply pipe 9 itself.

As illustrated in FIG. 8B, the second protruding portion 20 can beprovided along an entire circumference of an inner surface of the gassupply pipe 9 from a viewpoint of increasing the cross-sectional area ofthe gas supply pipe 9. Accordingly, generation of cracking or chippingdue to fatigue breakage or the like in the first joining portion 17joined to the gas supply pipe 9 can be suppressed.

Each of FIG. 9A, FIG. 9B, and FIG. 9C is a horizontal cross-sectionalview illustrating another non-limiting example of FIG. 8B.

Each of FIG. 9A and FIG. 9B illustrates a non-limiting example in whicha thickness of the gas supply pipe 9 at the second protruding portion 20is uneven along an entire circumference.

As in FIG. 9A, a thin portion and a thick portion may beline-symmetrical. Further, as in FIG. 9B, the thin portion and the thickportion may be eccentric. As described above, even when the thickness ofthe gas supply pipe 9 at the second protruding portion 20 is unevenalong the entire circumference, the gas supply pipe 9 remains thickwithout change, and generation of cracking or chipping due to theportion can be suppressed.

On the other hand, the second protruding portion 20 is not necessarilyrequired to be provided along the entire circumference. As in FIG. 9C,the second protruding portion 20 may be provided partially. Even in thecase where the second protruding portion 20 is provided partially asdescribed above, generation of cracking or chipping due to the portionat which the gas supply pipe 9 is thick can be suppressed.

The thickness of the gas supply pipe 9 can be, for example, from 0.5 mmto 1.0 mm, and the thickness of the second protruding portion 20 can be,for example, from 0.1 mm to 0.5 mm.

Each of FIG. 10 and FIG. 11 is an enlarged vertical cross-sectional viewillustrating another non-limiting example of section B of FIG. 7.

In a non-limiting example illustrated in FIG. 10, a second bent portion4 d extending toward a reformer 6 side along the gas supply pipe 9 isprovided in an outer periphery of the second through hole 15 in themanifold 4, and an upper end portion of the second bent portion 4 d andthe gas supply pipe 9 are joined via the second joining portion 18. Themanifold 4 includes the second bent portion 4 d, and thus the manifold 4and the gas supply pipe 9 are joined easily. Further, the gas supplypipe 9 is inserted into the second through hole 15 easily. Note that aheight H2 of the second bent portion 4 d can be, for example, from 2 mmto 5 mm.

In the non-limiting example illustrated in FIG. 11, a thickness t6 of anupper end portion of the second bent portion 4 d is larger than athickness t7 of a center portion the second bent portion 4 d and smallerthan a thickness t8 of a lower end portion of the second bent portion 4d. In other words, the second bent portion 4 d has such a shape that thecenter portion is recessed with respect to the upper end portion and thelower end portion expands. Accordingly, cross-sectional area of theupper end portion of the second bent portion 4 d increases, and thus theupper end portion of the second bent portion 4 d and the gas supply pipe9 are firmly joined via the second joining portion 18. Moreover, thecenter portion is recessed with respect to the upper end portion, andthus the thickness t7 of the center portion is the smallest among thethickness t6, the thickness t7, and the thickness t8. This centerportion having a small thickness can relieve stress generated when thegas supply pipe 9 is deformed or moves. Accordingly, the gas supply pipe9 and the manifold 4 can be joined firmly. Furthermore, the lower endportion of the second bent portion 4 d expands, and accordingly an angleformed between the second bent portion 4 d and the manifold 4 is obtuseto obtain a gently-sloping shape. Hence, stress generated when the gassupply pipe 9 is deformed or moves can be relieved. As a result,generation of cracking or chipping between the second bent portion 4 dand the manifold 4 can be suppressed.

At the second bent portion 4 d, the thickness t6 can be, for example,0.6 mm to 0.8 mm, the thickness t7 can be, for example, from 0.5 mm to0.6 mm, and the thickness t8 can be, for example, from 0.9 mm to 1.2 mm.

Description will be made of a non-limiting example of a method ofmanufacturing the manifold 4 according to a non-limiting embodimentdescribed above. In the following, detailed description will be made ona method of manufacturing the manifold 4 as illustrated in, for example,FIG. 7 in which the first through hole 14 is formed in the flangeportion 4 b and the second through hole 15 is formed in the main bodyportion 4 a.

The first through hole 14 is formed by penetrating the flange portion 4b by a processing method such as punching. Similarly, the second throughhole 15 is also formed by penetrating the main body portion 4 a by aprocessing method such as punching.

The first joining portion 17 and the second joining portion 18 to whichthe gas supply pipe 9 and the manifold 4 are joined can be provided byjoining an outer surface of the manifold 4 and the gas supply pipe 9 byusing a metallurgical joining method. The metallurgical joining methodis a method of performing joining by fusion welding, pressure welding,or soldering. Non-limiting examples of the fusion welding include laserwelding, plasma arc welding, inert gas arc welding, MAG welding, or gaswelding. Further, non-limiting examples of the pressure welding includeultrasonic welding, friction welding, or explosive welding.

Further, to provide the first bent portion 4 c and the second bentportion 4 d integrally with the outer peripheries of the first throughhole 14 and the second through hole 15, respectively in the manifold 4,a processing method such as pressing using dies having shapes of thefirst bent portion 4 c and the second bent portion 4 d can be performed.Further, in a case where the first bent portion 4 c and the second bentportion 4 d are provided separately from the outer peripheries of thefirst through hole 14 and the second through hole 15, respectively,members having shapes of the first bent portion 4 c and the second bentportion 4 d may be prepared, and the respective members may be joined tothe outer peripheries of the first through hole 14 and the secondthrough hole 15 by the metallurgical joining method described above.

FIG. 12 is an external perspective view illustrating a non-limitingexample of a fuel cell module serving as a module including the cellstack device 111 housed in a housing container, and the cell stackdevice 111 illustrated in FIG. 6A is housed inside a housing container22 having a rectangular parallelepiped shape.

Note that for the purpose of obtaining fuel gas to be used in the cells3, the reformer 6 configured to generate fuel gas by reforming raw fuelsuch as natural gas and kerosene is disposed above the cell stack 5.Then, the fuel gas generated in the reformer 6 is supplied to themanifold 4 via the gas supply pipe 9, and is supplied, via the manifold4, to the gas flow passages provided inside the cells 3.

Note that FIG. 12 illustrates a state in which portions (front and backsurfaces) of the housing container 22 are detached and the cell stackdevice 111 and the reformer 6 housed inside are removed to the rear. Ina module 30 illustrated in FIG. 12, the cell stack device 111 can behoused in the housing container 22 by being slid into the housingcontainer 22. Note that the cell stack device 111 may include thereformer 6.

Further, in the module 30 according to a non-limiting embodiment, thecell stack device 111 described above is housed in the housing container22, and hence the module 30 with improved durability can be obtained.

FIG. 13 is a perspective view illustrating a non-limiting example of afuel cell device serving as a module housing device in which the module30 illustrated in FIG. 12 and an auxiliary device configured to operatethe cell stack device 111 are housed in an external casing. Note that aportion of the configuration is omitted in FIG. 13.

In a module housing device 40 illustrated in FIG. 13, the externalcasing including supports 41 and exterior plates 42 is divided into anupper section and a lower section by a dividing plate 43. The uppersection serves as a module housing chamber 44 that houses the module 30described above. The lower section serves as an auxiliary device housingchamber 45 that houses the auxiliary device configured to operate themodule 30. Note that the auxiliary device housed in the auxiliary devicehousing chamber 45 is not illustrated.

Further, an airflow hole 46 is provided in the dividing plate 43. Theairflow hole 46 is configured to cause air in the auxiliary devicehousing chamber 45 to flow into the module housing chamber 44. Anexhaust hole 47 is provided in a portion of the outer plates 42constituting the module housing chamber 44. The exhaust hole 47 isconfigured to discharge air inside the module housing chamber 44.

As described above, in the module housing device 40, the module 30 withimproved durability is housed in the module housing chamber 44, andaccordingly the module housing device 40 with improved durability can beobtained.

Note that, for example, in a non-limiting embodiment described above,the description is made by using so-called vertical cells; however,horizontal cells referred to commonly as horizontal cells in which aplurality of power generating elements are provided on a supportsubstrate, or so-called cylindrical cells can also be used.

The non-limiting embodiments according to the present disclosure aredescribed above, but the present disclosure is not limited to theabove-described embodiments, and can have any embodiments as long as itdoes not depart from the spirit of the present disclosure.

REFERENCE SIGNS LIST

1, 111 Cell stack device

3 Cell

4 Manifold

-   -   4 a Main body portion    -   4 b Flange portion    -   4 c First bent portion    -   4 d Second bent portion

5 Cell stack

6 Gas supply portion (reformer)

9 Gas supply pipe

14 First through hole

15 Second through hole

17 First joining portion

18 Second joining portion

19 First protruding portion

20 Second protruding portion

30 Module (fuel cell module)

40 Module housing device (fuel cell device)

t1 Thickness of gas supply pipe at first protruding portion

-   -   t11 Thickness of gas supply pipe itself    -   t12 Maximum thickness of first protruding portion

t2 Thickness of gas supply pipe at second protruding portion

-   -   t21 Thickness of gas supply pipe itself    -   t22 Maximum thickness of second protruding portion

The invention claimed is:
 1. A cell stack device comprising: a cellstack in which a plurality of cells, each having a cylindrical shape andcomprising gas flow passages, are arranged uprightly and areelectrically connected; a manifold configured to fix lower ends of theplurality of cells and supply gas to the gas flow passages of theplurality of cells; and a gas supply pipe configured to supply the gasto the manifold; wherein the gas supply pipe comprises a first end ofthe gas supply pipe connected to a gas supply portion and a second endof the gas supply pipe inserted into a first through hole in themanifold, and is joined to the manifold via a first joining portion, andthe gas supply pipe comprises a first protruding portion protrudinginwards from an inner side of the gas supply pipe and located at aposition corresponding to the first joining portion in any cross-sectionalong an insertion direction of the gas supply pipe into the manifold.2. The cell stack device according to claim 1, wherein the firstprotruding portion is provided along an entire circumference of theinner surface of the gas supply pipe.
 3. The cell stack device accordingto claim 2, wherein a thickness of the gas supply pipe at the firstprotruding portion is uneven along an entire circumference.
 4. The cellstack device according to claim 1, wherein the manifold comprises afirst bent portion extending along the gas supply pipe toward the gassupply portion, and the first bent portion is provided along an outerperimeter of the first through hole; and a distal end portion of thefirst bent portion and the gas supply pipe are joined via the firstjoining portion.
 5. The cell stack device according to claim 4, whereina thickness of the distal end portion of the first bent portion islarger than a thickness of a central portion of the first bent portion,and is smaller than a thickness of a proximal end portion of the firstbent portion.
 6. The cell stack device according to claim 1, wherein themanifold further comprises a main body portion comprising a spaceconfigured to communicate with the gas flow passages, and a flangeportion protruding from the main body portion; the flange portioncomprises the first through hole, and the main body portion comprises asecond through hole; the second end of the gas supply pipe is insertedinto the second through hole, and the second end and the manifold arejoined via a second joining portion; and the gas supply pipe comprises asecond protruding portion protruding inwards from an inner side of thegas supply pipe and located at a position corresponding to the secondjoining portion in any cross-section along an insertion direction of thegas supply pipe into the manifold.
 7. The cell stack device according toclaim 6, wherein the second protruding portion is provided along anentire circumference of the inner surface of the gas supply pipe.
 8. Thecell stack device according to claim 7, wherein a thickness of the gassupply pipe at the second protruding portion is uneven along an entirecircumference.
 9. The cell stack device according to claim 6, whereinthe manifold further comprises a second bent portion extending along thegas supply pipe toward the gas supply portion, and the second bentportion is provided along an outer perimeter of the second through hole;and a distal end portion of the second bent portion and the gas supplypipe are joined via the second joining portion.
 10. The cell stackdevice according to claim 9, wherein a thickness of the distal endportion of the second bent portion is larger than a thickness of acentral portion of the second bent portion, and is smaller than athickness of a proximal end portion of the second bent portion.
 11. Amodule comprising: the cell stack device according to claim 1 housed ina housing container.
 12. A module housing device comprising: the moduleaccording to claim 11; and an auxiliary device configured to operate themodule, wherein the module and the auxiliary device are housed in anexternal casing.